<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            box-sizing: border-box;
        }
        @keyframes ani {
            0% {
                transform: translate(0,0);
            }
            25% {
                transform: translate(500px,0);
            }
            50% {
                transform: translate(500px,500px);
            }
            75% {
                transform: translate(0,500px);
            }
            100% {
                transform: translate(0,0);
            }
        }
        .dom {
            width: 50px;
            height: 50px;
            background-color: green;
            animation-name: ani;
            animation-duration: 5s;
            animation-iteration-count: infinite;
            animation-timing-function: linear;
        }

    </style>
</head>
<body>
    <div class="dom">

    </div>
</body>
</html>